Door latch



Nov. 3, 1931.

r1'. lKRoMEl-e nooR LATCH Filed Feb. 29. 192s Illini' 59 always automatically brought backto the4 Patented hier. 3, 1931* 'reo s'rnrss Parent olf-HCEV THEOIDOR XROMR, OF FREIBURG, IN BREISGAU, GERMANY, .ASSIGN'OR TO THEODOR nnoivrnn GESELLSCHAFT Mrr BESCHRNKTER nnnisoa'o, GERMANY" HAFTUNG, OF FREIBURG, IN'

DOOR LATCH Application med' February 29 1928, Serial No. 258,07a, and in Germany July 25, 1927.

My invention relates to latches of the class .intended for bolting the doors of ordinaryor store-rooms, safes and the like, and adapted to be opened by means of a handle as (El, weil as by key and wherein the latch is locked in the closed psition. The purpose of my invention is to produce a lock wherein by a suitable rotation of the key that causes the latch to move, the latter can be locked in the l@ closed position. This special purpose l reach by the -means specified below with reference to the accompanying drawings, in which liigs. l and 2 represent a view of the inside of the lockshown in the open position,

Vand a section on the line A--B respectively, Figs. 3 and l represent an inside view of the lock shown in the closed position, and a section on the line C-ll respectively, and

Fig. 5 is a view of the key.

According to the drawings, the lock has a latch plate a with three bolts o rigidly secured on same and projecting out of the lock casing h. The latch plate is controlled by a spring d which tends to push it and the bolt c into the closed position shown.

Against the action 'of the spring Z the latch may be retracted by means of a rod f provided with a knob e, when the tumblers g,

'30 it, i, with their longitudinal slots c register with the detent pin Z`(Figs. l and 2) which is rigidly secured to the latch. .'Ihe tumbler g is kept in position by a spring o fitted on the lock-wall and having a beak 'm projecting into the notches n, or 'w of this tumbler, 'and the tumbler z' is kept in position by the vmutual pressure of these tumblers.

middle tumbler L which is provided with a lower and an upper slot k remains., in known manner, with entire freedom to move and is unaiected by the spring .0. 'Ihe ward g ofthe key e (Flg. 5) is stepped for `coopera tion with the tumblers g," L, i.' When the key is withdrawn the tumbler h drops by its own weight into the lower position, thereby blocking theentry to the keyhole. The detent pin Z is free to move in the slot 7c when the latch a is shifted either by means of the rod or by means of the key, the bolts being The original locking position by the spring al whereby the plate a is controlled. The key is provided with a tapering front end portion y, which portion by inserting the key in the keyhole raises the tumbler 7L in such a 5l measure that the entry to the keyhole is open for the insertion of the key. By setting the 1 ltumblers g, z' or by displacing the latch plate by means of the ward g of the key shown in broken lines in lFig.l 3, entering into a gap r of a follower disc `s which is in engagement with the latch plate a the centre tumbler t is raised by the .key-ward until the lower slot k comes opposite the pin Z allowing the horizontal displacement of the latter. Thus the latch -can be retracted from within by pulling back the rod if and from withoutl by turning .the key and can be locked in the shot position by turning the key in the direction opposite to that which retracts the latch, the lock being thus secured against unwarranted opening. For this purpose, the front tumbler g possesses, advantageously a nose t, which projects into the gap p that admits the ward g'. rlihe ward bears with its respective step against the nose t and, by a` slight rotation of the key ward to the left', well over the keyhole width of the lock plate, (not shown in the drawings) moves the tumbler g from the position shown in Fig. 1 to that shown in Fig. 3. rlhe backs u of the tumblers place themselves in front of the pin Zand thus preventing a displacement of the pin Z in its open positionto secure the latch bolts in shot position. A

With the tumbler g. the tumblers i, are brought into the locking position by a :Eollower lv which is rigidly secured to the tum'- bler g and notched so as to allow the tumbler 7Lv to move. The tumbler g is retained in position by the spring o4 engaging in the notch fw, while the tumbler h which -is freely movable in the slot' of the U-shaped follower o drops by its own' weight into the lower position after the key has been removed from the keyhole and assists the other tumblers of the lock to ensure an effective locking of the latch plate as the tumbler k ater having vents the displacement of pin l by means of al nose u. Y

I claim:

In a key operated latched lock, the combination of a sliding latch bolt, a spring acting on said latch bolt, hand-operated means to actuate said latch bolt, a plurality of spring-controlled tumblers co-operating with said' latch bolt adaptedto be actuated by a key, a tumbler loosely mounted in front 'of the key hole, adapted to position itself be- -fore the hole under its own wei ht, slots in said loose tumbler, a detent in said latch bolt adapted to enter said slots, a key operated, sprlng controlled front tumbler, a nose on said front tumbler, an arched follower rigidly connected t'o said front tumbler adapted to transmit the locking movement thereof to the said spring controlled tumblers.

THEODOR KROMER. 

